Distance: 11 miles. Time: two hours. Difficulty: moderate. Water: two bottles.
This out-and-back ride heads northwest from San Miguel's center, passing the bus and train stations and linking up with local commuter bike trails in open countryside. Don't worry about crossing anyone's land: As long as there's a trailand there are scads of themtrespassing is not just allowed, but expected. This is cross-country heaven, with narrow, rock-free trails threading past cholla, nopal cacti, quail, and red-tailed hawks. San Miguel is far removed, dwarfed by the expanse of sky.
All northwest-tending tracks eventually cross the dusty, lane-and-a-half Cieneguitas road. At the end of this route are the Río Laja, San Miguel's main water source; the sugarcane-framed pueblo of Cieneguitas; and a relatively new hot springs facility called Las Grutas de Guadalupe ($2.50 to enter; bring your bathing suit). The five pools are big enough for a half-dozen people and overlook cornfields and tiny ranchos. Just don't soak too long or the gradual, uphill ride home will seem twice as steep.
Palo Colorado-Atotonílco Loop
Distance: 23.5 miles. Time: six hours. Difficulty: strenuous. Water: three bottles.
Be prepared for a day of technical ridinglots of rocks and swooping sandstone moguls. The loop begins at San Luis Rey and links up with the 300-year-old Camino Real, following its fractured path north along the mountains. You may have to push your bike over the trickier sections, but the sweeping views are well worth it, looking all the way to the Santa Rosa Mountains above Guanajuato, 35 miles away. After about two hours, you'll see willows that mark an abandoned hacienda. Aim toward these trees, descending for five miles into the White Desert, a sandstone playground that has some of the best banked runs and air-grabbing jumps this side of Fruita, Colorado.
The big attraction at Atotonílco, 10 miles from San Miguel, is the 18th-century Santuario, a pilgrimage center for penitentesmortifiers of the flesh. The World Monuments Fund recently helped renovate the church, with its fascinating Hieronymus Bosch-style frescoes depicting the horrors that await the unfaithful. Browse among the vendors for the perfect souvenir: a skin-piercing crown of thorns, perhaps, or a colorful rope whip for a dose of self-flagellation.
The ride back to San Miguel follows the old train bed. It's wide, well graded, and gently inclined, and after about 40 minutes it leads you to the Cieneguitas church and the road home.